Does KompWatch Work on JavaScript-Heavy Sites?

Yes — KompWatch uses a full headless browser (Playwright + Chromium) to render pages, not a simple HTTP fetcher. This means it captures the fully rendered DOM after JavaScript executes, including content built with React, Next.js, Vue, Angular, and other SPA frameworks.

How It Works for SPAs

Browser loads the page — Chromium opens the URL just like a real user's browser
JavaScript executes — the page runs its client-side rendering
Network settles — KompWatch waits for network activity to finish (network idle) before taking the snapshot
Rendered DOM captured — the final HTML seen by a real user is what gets diffed

This approach catches content that only appears after JavaScript runs — pricing loaded by API call, feature sections rendered client-side, etc.

Known Limitations

Session tokens / personalized content: If a page renders different content for different users (e.g., logged-in state), KompWatch will see the unauthenticated view. This is a known limitation with no workaround today.
Heavy animation or skeleton loaders: Some sites show a loading spinner and then swap in content. KompWatch's network-idle wait catches most of these, but sites with streaming or infinite scroll may require a specific CSS selector to target the stable portion of the page.
Bot detection: A small number of sites block headless browsers with advanced fingerprinting (Cloudflare, Akamai bot protection). KompWatch will log a warning in those cases and show a partial or empty snapshot.

Tips for SPA Sites

Use a CSS selector to target a stable container (e.g., .pricing-table, #features-section). This ignores dynamic sidebar content or navigation elements that change constantly.
Check your Change Severity settings — CSS-only changes from animations or rotating content are filtered as Low severity by default.
If a competitor site consistently produces noisy, irrelevant diffs, email support@kompwatch.com and we can help tune the selector.

Quick Test: Is My Competitor's Site Server-Rendered or SPA?

Press Cmd+U (Mac) or Ctrl+U (Windows) on your competitor's pricing page to view source:

See full readable content — pricing text, feature descriptions, plan names? That's a server-rendered site. Most monitoring tools work fine.
See <div id="root"></div> and a bundle of <script> tags with little else? That's a React, Next.js, or similar SPA. Tools that don't use a headless browser will silently snapshot an empty div and never fire a diff.

KompWatch uses Playwright with networkidle waiting, so both types work correctly.

Does KompWatch Follow Client-Side Navigation?

No — KompWatch monitors the URL you specify, not additional pages that load via client-side routing. To monitor multiple pages (e.g., /pricing, /features, /blog), add each as a separate competitor entry or separate URL.

Questions? Email support@kompwatch.com and we'll respond within 24 hours.